The present invention relates to a sheet storing device capable of storing a plurality of sheets and feeding out stored sheets, and to an image forming apparatus provided with the sheet storing device.
There is known recently that a finisher is connected to an image forming apparatus of an electrophotographic type to create a shortrun-printing machine in which a booklet is made by printing on the obverse and the reverse of a sheet and by bounding sheets in order of pages. In the case of making a booklet in this way, highly accurate registering between a sheet and an image is needed. For example, when binding a booklet and spreading its pages after printing on the obverse and the reverse of a sheet, if images on the obverse and the reverse are poorly registered, the bookbinding is poor in quality. When cutting sheet edges after a plurality of sheets are bound, if an image is not formed at a correct position on a sheet, there is a danger of an accident that a part of an image is cut to be missing.
In the image forming apparatus of this kind, it is required that an image is formed at a correct position on a sheet, and in a sheet storing device in the image forming apparatus, it is necessary to store sheets at an appropriate position by using a sheet regulating member. If sheets are stored at an appropriate position, a sheet can be fed out of the sheet storing device without skewing and bias, whereby, an image is formed at a correct position on the sheet.
With respect to a sheet regulating member in a sheet storing device, it is described in Unexamined Japanese Patent Application Publication No. 2005-60064. In the sheet storing device described in Japanese Patent Application Publication No. 2005-60064, there are provided a leading edge regulating member that regulates a position of a leading edge in the sheet feeding direction of a sheet, a pair of side regulating members that regulate positions of both sides of the sheet in the direction perpendicular to the sheet feeding direction and a trailing edge regulating member that regulates a position of a trailing edge of a sheet in the sheet feeding direction.
However, even when a position of a sheet is tried to be regulated by the leading edge regulating member described in Unexamined Japanese Patent Application Publication No. 2005-60064, there is occasionally the case that a gap is caused between a sheet and the leading edge regulating member, by degrees of precision of parts in the leading edge regulating member and by bending in the sheet storing device, which makes it impossible to regulate a sheet at a correct position.